1. Field of the Invention
The present invention relates to a connector for a coaxial cable, and more particularly, to a connector for a coaxial cable that secures a high-reliability electrical contact although there are changes in an inner diameter of a hollow inner conductor of the coaxial cable.
2. Description of the Related Art
A coaxial cable comprises an inner conductor that is a medium of signal transmission, an insulator surrounding the inner conductor, an outer conductor surrounding the insulator, and a sheath surrounding the outer conductor. The coaxial cable is more strongly resistant to interference of external electromagnetic waves than other cables, and thus, it is currently used in many industrial fields.
The inner conductor of the coaxial cable may have a shape of a solid cylinder or a hollow cylinder. Generally, the solid cylinder-shaped inner conductor is used to a coaxial cable having a relatively smaller diameter, and the hollow cylinder-shaped inner conductor is used to a coaxial cable having a relatively larger diameter. And, the outer conductor of the coaxial cable may have a flat type and a corrugated type. A coaxial cable with the flat type outer conductor allows easy manufacturing and small diameter, and a coaxial cable with the corrugated type outer conductor allows relatively better properties of signal attenuation and cable bending.
For a special purpose of use, the coaxial cable needs to be electrically connected with other coaxial cables or electrical equipments such as a measuring equipment, an operating equipment, a control equipment and so on. For example, the coaxial cable may be connected with another coaxial cable for extending the length of a signal transmission line. The coaxial cable may be connected with a measuring equipment for quality test. The coaxial cable may be electrically connected with an operating equipment and a control equipment for signal transmission therebetween.
A connector is used to connect the coaxial cable with another coaxial cable or an electrical equipment. The connector comprises a pin, a housing, and an insulator. The pin connects an inner conductor of a coaxial cable with an inner conductor of another coaxial cable or an inner conductor of a coaxial cable with a signal receiving/transmitting unit of an electrical equipment. The housing connects an outer conductor of a coaxial cable with an outer conductor of another coaxial cable or an outer conductor of a coaxial cable with a ground of an electric equipment. The insulator insulates the pin from the housing.
In the case that the inner conductor is a hollow inner conductor, the pin of the connector is inserted into a hollow of the inner conductor. The pin inserted into the hollow of the inner conductor is contacted with the inner surface of the inner conductor. In this way, the coaxial cable is electrically coupled with the connector. At this time, if a contact between the pin of the connector and the inner conductor of the coaxial cable is incomplete, a signal flowing toward the inner conductor may be distorted or attenuated while passing through the connector. For this reason, a complete contact should be guaranteed between the pin of the connector and the inner conductor of the coaxial cable.
However, a pin of a conventional connector has a fixed diameter. Thus, when the pin is inserted into an inner conductor having a larger inner diameter than a diameter of the pin, a contact between the pin and the inner conductor is not guaranteed to be complete.